Rock Band 2 Instruments not working

[Alternity]

The Wii version of Rock Band (all editions) were never updated in any way because the Wii console itself does not lend itself well to games being updated, so that's not your problem.

The game isn't updated, but the first time you boot any RB games it will update the system to install the necessery IOS files for the instruments to work, like DLLs on windows. If this process was halted, or never happened, this is where the problem is. If the console was homebrewed, this is most likely it, however, I am probably not permitted to dicuss the solution on here if this is the case.